All categories

3 years ago

Eventually, everyone must sleep due to our (1 point) need for mental rest. beta waves. biological rhythms. delta waves.

1 answer:

6 0

Out of the available answers, the most likely correct would be that eventually everyone must sleep due to our need for mental rest. However, it is not as simple as this, as all of the processes implicated with mental rest (including the restoration of biological rhythms as mentioned in an alternative answer) cannot necessarily be summed up in this way.

You might be interested in

How many milliliters of 0.02 M HCl are needed to react completely with 100 mL of 0.01 M NaOH?

serious [3.7K]

The reaction of HCl and NaOH is HCl + NaOH = NaCl + H2O. So the mole number of HCl and NaOH is equal. So the volume of HCl =0.01*0.1/0.02=0.05 L =50 ml. So the answer is D).

3 0

4 years ago

Read 2 more answers

Calculate the ΔG°rxn using the following information at 298K. 2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) ΔG°rxn = ? ΔH°f (kJ/mol) -2

Mkey [24]

Answer:

ΔG°rxn = +50.8 kJ/mol

Explanation:

It is possible to obtain ΔG°rxn of a reaction at certain temperature from ΔH°rxn and S°rxn, thus:

ΔG°rxn = ΔH°rxn - T×S°rxn (1)

In the reaction:

2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l)

ΔH°rxn = 3×ΔHfNO2 + ΔHfH2O - (2×ΔHfHNO3 + ΔHfNO)

ΔH°rxn = 3×33.2kJ/mol + (-285.8kJ/mol) - (2×-207.0kJ/mol + 91.3kJ/mol)}

ΔH°rxn = 136.5kJ/mol

And S°:

S°rxn = 3×S°NO2 + S°H2O - (2×S°HNO3 + S°NO)

ΔH°rxn = 3×0.2401kJ/molK + (0.0700kJ/molK) - (2×0.146kJ/molK + 0.2108kJ/molK)

ΔH°rxn = 0.2875kJ/molK

And replacing in (1) at 298K:

ΔG°rxn = 136.5kJ/mol - 298K×0.2875kJ/molK

ΔG°rxn = +50.8 kJ/mol

7 0

3 years ago

Read 2 more answers

Write the full ionic equation and net ionic equation for sodium dihydrogen phosphate + calcium carbonate, sodium oxilate + calcl

My name is Ann [436]

Answer:

Sodium dihydrogen phosphate + calcium carbonate

Full ionic equation

2 Na⁺(aq) + 2 H₂PO₄⁻(aq) + CaCO₃(s) ⇄ 2 Na⁺(aq) + CO₃²⁻(aq) + Ca(H₂PO₄)₂(s)

Net ionic equation

2 H₂PO₄⁻(aq) + CaCO₃(s) ⇄ CO₃²⁻(aq) + Ca(H₂PO₄)₂(s)

Sodium oxalate + calcium carbonate

Full ionic equation

2 Na⁺(aq) + C₂O₄²⁻(aq) + CaCO₃(s) ⇄ 2 Na⁺(aq) + CO₃²⁻(aq) + CaC₂O₄(s)

Net ionic equation

C₂O₄²⁻(aq) + CaCO₃(s) ⇄ CO₃²⁻(aq) + CaC₂O₄(s)

Sodium hydrogen phosphate + calcium carbonate

Full ionic equation

2 Na⁺(aq) + HPO₄²⁻(aq) + CaCO₃(s) ⇄ CaHPO₄(s) + 2 Na⁺(aq) + CO₃²⁻(aq)

Net ionic equation

HPO₄²⁻(aq) + CaCO₃(s) ⇄ CaHPO₄(s) + CO₃²⁻(aq)

Explanation:

Let's consider two kind of equations:

Full ionic equation: includes all ions and species that do not dissociate in water.
Net ionic equation: includes only ions that participate in the reaction (not spectator ions) and species that do not dissociate in water.

4 0

3 years ago

Which is the best conductor of electricity (0.1M solution)? Why?

Semmy [17]

Answer:

sulphuric acid as it is strong electrolyte and thus, ionises completely.

Explanation:

3 0

3 years ago

Read 2 more answers

You wish to prepare a buffer consisting of acetic acid and sodium acetate with a total acetic acetate plus acetate concentration

vovangra [49]

Ans: Acetic acid = 90.3 mM and Sodium acetate = 160 mM

Given:

Acetic Acid/Sodium Acetate buffer of pH = 5.0

Let HA = acetic acid

A- = sodium acetate

Total concentration [HA] + [A-] = 250 mM ------(1)

pKa(acetic acid) = 4.75

Based on Henderson-Hasselbalch equation

pH = pKa + log[A-]/[HA]

[A-]/[HA] = 10^(pH-pKa) = 10^(5-4.75) = 10^0.25 = 1.77

[A-] = 1.77[HA] -----(2)

From (1) and (2)

[HA] + 1.77[HA] = 250 mM

[HA] = 250/2.77 = 90.25 mM

[A-] = 1.77(90.25) = 159.74 mM

7 0

4 years ago